Compact Floor-standing Speaker Recommendations under $4k

Why floor standers? A stand mount speaker will take up the same amount of space. If floor stander is a must, then the Spendor A2's are right at or near your budget.

ProAcs and Spendors are great within their capabilities, but they're pretty spendy for a 6-7" 2-driver tower, which in turn is pretty limited dynamically - only so much a single 6" woofer can do, both in the low bass and upper mids. My plug for Monitor Audio Silver 300 7G (2X6" woofers) or 500 (2X8" woofer). Stupendously good speakers, regardless of their price, which is about half either the ProAc or Spendor. Read the reviews from Absolute Sound, Stereophile, etc. If you have the room, then also definitely check out the Magnepan 1.7. Yes, they take lots of power, and no, they wont bowl you over with their bass, but, setup and fed properly, they are simply superb. If they worked in my room, I'd have a pair in a heartbeat. As it is I have a pair of the smallest  Maggies I keep around for for fun, even if I can't set them up ideally. 

may I suggest acoustic zen adagios

and the fritz loudspeaker om his stand 

Your dilemma sounds like a scenario where a pair of Harbeth speakers would be all you need. 

Thanks again for all your feedback and advice! 

So many smaller speaker companies I wasn't familiar with so I'm trying to research all the prosed options.  I know it's going to be system and personal preference dependent but you've all given me such great starting points.  

The Spendor A7's are still high on my list and I've seen used offerings within my price range (several on other sites around $3.5k in what appears to be excellent condition; the MSRP seems high but at the second hand price it might be a much better value proposition). 

The Salk (which I think now makes the Philharmonic BMR's as well), ATC, Verity, ProAc's and Acoustic Zen are all in contention.  The Sonus Faber recommendation also is intriguing, but there seems to be a real love/hate impression on their speakers overall...although I must admit they look beautiful it seems a bit riskier to try them out without demo-ing first. 

And as far as the questions as to why floor-standers.  I suppose ultimately, that's not critical however I was thinking it may be easier to get better bass depth with the floor stander additionally I believe the stand itself is critical to the performance on bookshelf speakers and from what I've seen the stands alone can easily get into the $500 - $1k range which ultimately reduces my budget for the speaker itself.  Now my logic may be slightly flawed so I'm open to bookshelf suggestions, however I was trying to narrow my scope a bit or I open the flood gates to possibilities.